I don't know how much your son is into the whole "racing" thing, but it you want to really involve him, Sears Point is a good place to do it. I mentioned a stopwatch in the other thread, also give him the air pressure gauge, and have him take your hot pressures when you return to the paddock. If you have a basic radio setup, he can spot for you. If he crosses the bridge out to grandstand by the scoring tower
seen here he can see from the entry to the carousel all the way to past turn 10, then from the turn onto the front straight to the crest of the hill. (you walk back and forth on the grandstand depending on what section of the track you want to watch) You can see almost as much from the main grandstand, but you can't see untill the cars exit the carousel, and lose sight at the bridge going up the hill.
Having a spotter with a radio is handy, lets you know if someong what the traffic is you can't see, and report trouble if there is any.
If you are planning on building a race car for the POC, you need to break in your crew chief.
Just a thought.
Tom